stmmac: add DMA support for GMAC 4.xx

DMA behavior is linked to descriptor management:

-descriptor mechanism (Tx for example, but it is exactly the same for RX):
-useful registers:
-DMA_CH#_TxDesc_Ring_Len: length of transmit descriptor ring
-DMA_CH#_TxDesc_List_Address: start address of the ring
	-DMA_CH#_TxDesc_Tail_Pointer: address of the last
					      descriptor to send + 1.
	-DMA_CH#_TxDesc_Current_App_TxDesc: address of the current
						    descriptor

-The descriptor Tail Pointer register contains the pointer to the
 descriptor address (N). The base address and the current
 descriptor decide the address of the current descriptor that the
 DMA can process. The descriptors up to one location less than the
 one indicated by the descriptor tail pointer (N-1) are owned by
 the DMA. The DMA continues to process the descriptors until the
 following condition occurs:
 "current descriptor pointer == Descriptor Tail pointer"

Then the DMA goes into suspend mode. The application must perform
a write to descriptor tail pointer register and update the tail
pointer to have the following condition and to start a new transfer:
"current descriptor pointer < Descriptor tail pointer"

The DMA automatically wraps around the base address when the end
of ring is reached.

Up to 8 DMA could be use but currently we only use one (channel0)

Signed-off-by: Alexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 202 insertions, 0 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.h b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.h
new file mode 100644
index 000000000000..1b06df749e2b
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.h
@@ -0,0 +1,202 @@
+/*
+ * DWMAC4 DMA Header file.
+ *
+ *
+ * Copyright (C) 2007-2015  STMicroelectronics Ltd
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * Author: Alexandre Torgue <alexandre.torgue@st.com>
+ */
+
+#ifndef __DWMAC4_DMA_H__
+#define __DWMAC4_DMA_H__
+
+/* Define the max channel number used for tx (also rx).
+ * dwmac4 accepts up to 8 channels for TX (and also 8 channels for RX
+ */
+#define DMA_CHANNEL_NB_MAX		1
+
+#define DMA_BUS_MODE			0x00001000
+#define DMA_SYS_BUS_MODE		0x00001004
+#define DMA_STATUS			0x00001008
+#define DMA_DEBUG_STATUS_0		0x0000100c
+#define DMA_DEBUG_STATUS_1		0x00001010
+#define DMA_DEBUG_STATUS_2		0x00001014
+#define DMA_AXI_BUS_MODE		0x00001028
+
+/* DMA Bus Mode bitmap */
+#define DMA_BUS_MODE_SFT_RESET		BIT(0)
+
+/* DMA SYS Bus Mode bitmap */
+#define DMA_BUS_MODE_SPH		BIT(24)
+#define DMA_BUS_MODE_PBL		BIT(16)
+#define DMA_BUS_MODE_PBL_SHIFT		16
+#define DMA_BUS_MODE_RPBL_SHIFT		16
+#define DMA_BUS_MODE_MB			BIT(14)
+#define DMA_BUS_MODE_FB			BIT(0)
+
+/* DMA Interrupt top status */
+#define DMA_STATUS_MAC			BIT(17)
+#define DMA_STATUS_MTL			BIT(16)
+#define DMA_STATUS_CHAN7		BIT(7)
+#define DMA_STATUS_CHAN6		BIT(6)
+#define DMA_STATUS_CHAN5		BIT(5)
+#define DMA_STATUS_CHAN4		BIT(4)
+#define DMA_STATUS_CHAN3		BIT(3)
+#define DMA_STATUS_CHAN2		BIT(2)
+#define DMA_STATUS_CHAN1		BIT(1)
+#define DMA_STATUS_CHAN0		BIT(0)
+
+/* DMA debug status bitmap */
+#define DMA_DEBUG_STATUS_TS_MASK	0xf
+#define DMA_DEBUG_STATUS_RS_MASK	0xf
+
+/* DMA AXI bitmap */
+#define DMA_AXI_EN_LPI			BIT(31)
+#define DMA_AXI_LPI_XIT_FRM		BIT(30)
+#define DMA_AXI_WR_OSR_LMT		GENMASK(27, 24)
+#define DMA_AXI_WR_OSR_LMT_SHIFT	24
+#define DMA_AXI_RD_OSR_LMT		GENMASK(19, 16)
+#define DMA_AXI_RD_OSR_LMT_SHIFT	16
+
+#define DMA_AXI_OSR_MAX			0xf
+#define DMA_AXI_MAX_OSR_LIMIT ((DMA_AXI_OSR_MAX << DMA_AXI_WR_OSR_LMT_SHIFT) | \
+				(DMA_AXI_OSR_MAX << DMA_AXI_RD_OSR_LMT_SHIFT))
+
+#define DMA_SYS_BUS_MB			BIT(14)
+#define DMA_AXI_1KBBE			BIT(13)
+#define DMA_SYS_BUS_AAL			BIT(12)
+#define DMA_AXI_BLEN256			BIT(7)
+#define DMA_AXI_BLEN128			BIT(6)
+#define DMA_AXI_BLEN64			BIT(5)
+#define DMA_AXI_BLEN32			BIT(4)
+#define DMA_AXI_BLEN16			BIT(3)
+#define DMA_AXI_BLEN8			BIT(2)
+#define DMA_AXI_BLEN4			BIT(1)
+#define DMA_SYS_BUS_FB			BIT(0)
+
+#define DMA_BURST_LEN_DEFAULT		(DMA_AXI_BLEN256 | DMA_AXI_BLEN128 | \
+					DMA_AXI_BLEN64 | DMA_AXI_BLEN32 | \
+					DMA_AXI_BLEN16 | DMA_AXI_BLEN8 | \
+					DMA_AXI_BLEN4)
+
+#define DMA_AXI_BURST_LEN_MASK		0x000000FE
+
+/* Following DMA defines are chanels oriented */
+#define DMA_CHAN_BASE_ADDR		0x00001100
+#define DMA_CHAN_BASE_OFFSET		0x80
+#define DMA_CHANX_BASE_ADDR(x)		(DMA_CHAN_BASE_ADDR + \
+					(x * DMA_CHAN_BASE_OFFSET))
+#define DMA_CHAN_REG_NUMBER		17
+
+#define DMA_CHAN_CONTROL(x)		DMA_CHANX_BASE_ADDR(x)
+#define DMA_CHAN_TX_CONTROL(x)		(DMA_CHANX_BASE_ADDR(x) + 0x4)
+#define DMA_CHAN_RX_CONTROL(x)		(DMA_CHANX_BASE_ADDR(x) + 0x8)
+#define DMA_CHAN_TX_BASE_ADDR(x)	(DMA_CHANX_BASE_ADDR(x) + 0x14)
+#define DMA_CHAN_RX_BASE_ADDR(x)	(DMA_CHANX_BASE_ADDR(x) + 0x1c)
+#define DMA_CHAN_TX_END_ADDR(x)		(DMA_CHANX_BASE_ADDR(x) + 0x20)
+#define DMA_CHAN_RX_END_ADDR(x)		(DMA_CHANX_BASE_ADDR(x) + 0x28)
+#define DMA_CHAN_TX_RING_LEN(x)		(DMA_CHANX_BASE_ADDR(x) + 0x2c)
+#define DMA_CHAN_RX_RING_LEN(x)		(DMA_CHANX_BASE_ADDR(x) + 0x30)
+#define DMA_CHAN_INTR_ENA(x)		(DMA_CHANX_BASE_ADDR(x) + 0x34)
+#define DMA_CHAN_RX_WATCHDOG(x)		(DMA_CHANX_BASE_ADDR(x) + 0x38)
+#define DMA_CHAN_SLOT_CTRL_STATUS(x)	(DMA_CHANX_BASE_ADDR(x) + 0x3c)
+#define DMA_CHAN_CUR_TX_DESC(x)		(DMA_CHANX_BASE_ADDR(x) + 0x44)
+#define DMA_CHAN_CUR_RX_DESC(x)		(DMA_CHANX_BASE_ADDR(x) + 0x4c)
+#define DMA_CHAN_CUR_TX_BUF_ADDR(x)	(DMA_CHANX_BASE_ADDR(x) + 0x54)
+#define DMA_CHAN_CUR_RX_BUF_ADDR(x)	(DMA_CHANX_BASE_ADDR(x) + 0x5c)
+#define DMA_CHAN_STATUS(x)		(DMA_CHANX_BASE_ADDR(x) + 0x60)
+
+/* DMA Control X */
+#define DMA_CONTROL_MSS_MASK		GENMASK(13, 0)
+
+/* DMA Tx Channel X Control register defines */
+#define DMA_CONTROL_TSE			BIT(12)
+#define DMA_CONTROL_OSP			BIT(4)
+#define DMA_CONTROL_ST			BIT(0)
+
+/* DMA Rx Channel X Control register defines */
+#define DMA_CONTROL_SR			BIT(0)
+
+/* Interrupt status per channel */
+#define DMA_CHAN_STATUS_REB		GENMASK(21, 19)
+#define DMA_CHAN_STATUS_REB_SHIFT	19
+#define DMA_CHAN_STATUS_TEB		GENMASK(18, 16)
+#define DMA_CHAN_STATUS_TEB_SHIFT	16
+#define DMA_CHAN_STATUS_NIS		BIT(15)
+#define DMA_CHAN_STATUS_AIS		BIT(14)
+#define DMA_CHAN_STATUS_CDE		BIT(13)
+#define DMA_CHAN_STATUS_FBE		BIT(12)
+#define DMA_CHAN_STATUS_ERI		BIT(11)
+#define DMA_CHAN_STATUS_ETI		BIT(10)
+#define DMA_CHAN_STATUS_RWT		BIT(9)
+#define DMA_CHAN_STATUS_RPS		BIT(8)
+#define DMA_CHAN_STATUS_RBU		BIT(7)
+#define DMA_CHAN_STATUS_RI		BIT(6)
+#define DMA_CHAN_STATUS_TBU		BIT(2)
+#define DMA_CHAN_STATUS_TPS		BIT(1)
+#define DMA_CHAN_STATUS_TI		BIT(0)
+
+/* Interrupt enable bits per channel */
+#define DMA_CHAN_INTR_ENA_NIE		BIT(16)
+#define DMA_CHAN_INTR_ENA_AIE		BIT(15)
+#define DMA_CHAN_INTR_ENA_NIE_4_10	BIT(15)
+#define DMA_CHAN_INTR_ENA_AIE_4_10	BIT(14)
+#define DMA_CHAN_INTR_ENA_CDE		BIT(13)
+#define DMA_CHAN_INTR_ENA_FBE		BIT(12)
+#define DMA_CHAN_INTR_ENA_ERE		BIT(11)
+#define DMA_CHAN_INTR_ENA_ETE		BIT(10)
+#define DMA_CHAN_INTR_ENA_RWE		BIT(9)
+#define DMA_CHAN_INTR_ENA_RSE		BIT(8)
+#define DMA_CHAN_INTR_ENA_RBUE		BIT(7)
+#define DMA_CHAN_INTR_ENA_RIE		BIT(6)
+#define DMA_CHAN_INTR_ENA_TBUE		BIT(2)
+#define DMA_CHAN_INTR_ENA_TSE		BIT(1)
+#define DMA_CHAN_INTR_ENA_TIE		BIT(0)
+
+#define DMA_CHAN_INTR_NORMAL		(DMA_CHAN_INTR_ENA_NIE | \
+					 DMA_CHAN_INTR_ENA_RIE | \
+					 DMA_CHAN_INTR_ENA_TIE)
+
+#define DMA_CHAN_INTR_ABNORMAL		(DMA_CHAN_INTR_ENA_AIE | \
+					 DMA_CHAN_INTR_ENA_FBE)
+/* DMA default interrupt mask for 4.00 */
+#define DMA_CHAN_INTR_DEFAULT_MASK	(DMA_CHAN_INTR_NORMAL | \
+					 DMA_CHAN_INTR_ABNORMAL)
+
+#define DMA_CHAN_INTR_NORMAL_4_10	(DMA_CHAN_INTR_ENA_NIE_4_10 | \
+					 DMA_CHAN_INTR_ENA_RIE | \
+					 DMA_CHAN_INTR_ENA_TIE)
+
+#define DMA_CHAN_INTR_ABNORMAL_4_10	(DMA_CHAN_INTR_ENA_AIE_4_10 | \
+					 DMA_CHAN_INTR_ENA_FBE)
+/* DMA default interrupt mask for 4.10a */
+#define DMA_CHAN_INTR_DEFAULT_MASK_4_10	(DMA_CHAN_INTR_NORMAL_4_10 | \
+					 DMA_CHAN_INTR_ABNORMAL_4_10)
+
+/* channel 0 specific fields */
+#define DMA_CHAN0_DBG_STAT_TPS		GENMASK(15, 12)
+#define DMA_CHAN0_DBG_STAT_TPS_SHIFT	12
+#define DMA_CHAN0_DBG_STAT_RPS		GENMASK(11, 8)
+#define DMA_CHAN0_DBG_STAT_RPS_SHIFT	8
+
+int dwmac4_dma_reset(void __iomem *ioaddr);
+void dwmac4_enable_dma_transmission(void __iomem *ioaddr, u32 tail_ptr);
+void dwmac4_enable_dma_irq(void __iomem *ioaddr);
+void dwmac410_enable_dma_irq(void __iomem *ioaddr);
+void dwmac4_disable_dma_irq(void __iomem *ioaddr);
+void dwmac4_dma_start_tx(void __iomem *ioaddr);
+void dwmac4_dma_stop_tx(void __iomem *ioaddr);
+void dwmac4_dma_start_rx(void __iomem *ioaddr);
+void dwmac4_dma_stop_rx(void __iomem *ioaddr);
+int dwmac4_dma_interrupt(void __iomem *ioaddr,
+			 struct stmmac_extra_stats *x);
+void dwmac4_set_rx_ring_len(void __iomem *ioaddr, u32 len);
+void dwmac4_set_tx_ring_len(void __iomem *ioaddr, u32 len);
+void dwmac4_set_rx_tail_ptr(void __iomem *ioaddr, u32 tail_ptr, u32 chan);
+void dwmac4_set_tx_tail_ptr(void __iomem *ioaddr, u32 tail_ptr, u32 chan);
+
+#endif /* __DWMAC4_DMA_H__ */